The Rockdale Rockshelter (18BA70) is a Late Woodland campsite located beneath a rock outcropping at the base of a deep-gradient, narrow stream bed on an unnamed tributary of the Prettyboy Watershed approximately 1500 feet west of the Big Gunpowder Falls in northern Baltimore County.

Archaeological Investigations

The Rockdale Rockshelter archaeological site was first identified by Betty Fisher, an artifact collector and member of the Central Chapter of the Archaeological Society of Maryland (ASM) in 1971 in an interview with Tyler Bastian.  Two related rockshelter sites (18BA70a and 18BA70b) were recorded by Kate Quinn in 1980.

Avocational excavation and collection of the rockshelter took place in the 1960’s.  During the 1990’s, the ASM’s Central Chapert’s Gunpowder Falls Rockshelter Survey team explored, recorded, and studied various rockshelter sites (including 18BA70) in the vicinity of Prettyboy Reservoir.

The Central Chapter conducted test excavations at the Rockdale Rockshelter during Maryland Archaeology Month in April 2007.  This effort aimed to determine the extent of unsystematic excavations and disturbance within the rockshelter, and to explore the research potential of intact archaeological resources. 

The 2007 excavations were conducted in 5 cm levels in the upper A-Horizon and in 10 cm levels in the lower B-Horizon and C-Horizon.  All excavated soils were waterscreened, and two liter soil samples were retained for flotation from each level and 100% of feature fill was retained for flotation.

Typed projectile points and grit, sand and mica tempered ceramic sherds indicate that the shelter served a s Late Woodland foraging and hunting camp for gathering natural resources.  Modest midden development within the shelter suggests that the camp was used seasonally or sporadically by prehistoric people moving between the Chesapeake coastal plain and piedmont regions.

Archeobotanical Studies

Three flotation samples totaling approximately nine liters were processed and analyzed as part of the 2007 research effort.  One sample was secured from Feature 1, a shallow fire-reddened soil feature believed to be a prehistoric Late Woodland hearth.  The other two samples provided control samples collected from non-cultural contexts.

A total of 33.90 grams of carbonized archeobotanical remains were recovered from the processed flotation samples.   Recovered plant remains included wood charcoal, leaf fragments, and non-carbonized seeds.  A total of 3,485 fragments of burned wood were recovered.  Of these, a sub-sample of 60 fragments (a maximum of 20 fragments per sample) was randomly selected for identification.   White oak (Quercus spp. (LEUCOBALNUS group) wood charcoal was the most abundant and ubiquitous wood type encountered (52 fragments or 87 percent of the sub-sample selected for identification), with American chestnut (Castanea dentata), red oak (Quercus spp. ERYTHROBALANUS group) and walnut (JUGLANDACEAE) also identified.  Five fragments (eight percent) were classifiable only as ‘ring porous’. Three small leaf penducle fragments were recovered from the control sample taken from Unit 2 (Lot No. 32).Non-carbonized seeds occurred in all of the flotation samples analyzed – being most abundant within the control sample secured from north of Feature 3 (Lot No. 29).  Eight taxa were identified, representing both woody and herbaceous taxa.  Many of these uncarbonized seeds are from edible nuts and fruits, and may represent the remains of food cached by rodents. 

The study of archeobotanical materials within the Rockdale Rockshelter suggests that the shelter deposits have been compromised by rodent activities and perhaps scouring by flood episodes.


Israel, Stephen S.
2007 Archeological Excavations at the Rockdale Rockshelter (18BA70) Baltimore County, Maryland.
Israel, Stephen S., and Jim M. Davis
1992 An Archaeological Reconnaissance of Rockshelter Sites on the Big Gunpowder Falls, Baltimore County, Maryland.  Archaeological Society of Maryland.  MHT #70.
McKnight, Justine W.
2007 Report on the Analysis of Flotation-recovered Plant Remains from the Rockdale Rockshelter (18BA70), Baltimore County, Maryland.  Submitted to Stephen Israel on November 11.

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